158) In drilling softer materials, the cutting speed is ______ As compared to harder materials.

159) High speed steel drills can be operated at about ______ the speed of high carbon steel drills

160) The tap used to cut threads in a blind hole is

161) the hole to be drilled for tapping is ______ the outside diameter of the thread on the tap.

162) In which of the following machine, the work remains stationary and the tool is rotated?